This invention relates to improved nonpigmented wood stains suitable for use on unprimed hardwood surfaces. In a preferred embodiment, the invention relates to such improved stains which are supplied in gelled form.
In U.S. Pat. No. 4,187,072, issued Feb. 5, 1980 to J. Fernandez, there is disclosed a novel nonpigmented aromatic alcohol-based wood stain prepared in gelled form from aniline dyestuffs, benzyl alcohol as solvent and dibenzylidene sorbitol as gellant therefor. While these wood stains provide superior ease of application and penetration on hard wood surfaces, their use often requires the application of a primer, such as a coat of Danish oil, in order to obtain superior performance as disclosed in the aforementioned patent.
The need for a priming coat is due to several factors, one of which has to do with coniferous woods. When the stains of the aforementioned patent are applied directly onto unprimed softwoods, "fish-eye" or spots develop which are less frequently seen on hardwoods. The cause of these spots is surmised to arise from uneven wetting around resin-laden areas in the softwoods. It has therefore been found necessary in using these stains to first prime the wood surface to be stained with a penetrating oil such as Danish or Teak oil or another primer in order to avoid faults in the final stained surface.
While the use of a primer on a softwood surface has one side benefit, i.e. it develops a greater range of color densities and therefore a better overall development of subtle patterns of the wood, its use on hardwoods has a generally detrimental effect. It renders it difficult for the user to obtain very deep shades in hardwood finishes since the oil coating prevents penetration of sufficient stain to obtain the desired darker tones. Moreover, the use of a primer on hardwoods as ash and oak often results in an undesirable "zebra-like" pattern caused by differences in tracheid sizes of the early and late wood areas of the surface being stained.
It is therefore an object of the present invention to provide a non-pigmented gelled wood stain formulation which does not necessitate the use of a primer regardless of the type of wood surface to be treated.
It is also an object of the invention to provide a nonpigmented nongelled wood stain formulation which does not require the use of primers to ensure uniform penetration.
These and other objects will be apparent from the disclosure and examples which follow.